Treatment Initiation Among Black and White Older Adults With Multiple Myeloma: A SEER-Medicare Analysis

This study aims to describe time to treatment initiation for Black and White older adults with multiple myeloma (MM), and to test the hypothesis that Black/White disparities in treatment initiation have increased over time.

Black and White older adults (65+) diagnosed with myeloma 2007-2017 were identified in the SEER-Medicare database. Continuous Medicare Parts A/B coverage 12 months before and after diagnosis or until death, and Part D coverage for 12 months following diagnosis or until death were required for inclusion. We explored time to treatment initiation by race across three diagnosis time periods (2007-10, 2011-2014, 2015-2017) using Cox proportional hazard models. We estimated cumulative incidence of treatment initiation by race at 3, 6, and 12 months after diagnosis for all time periods.

White MM patients were more likely to initiate treatment than Black MM patients across time periods. Hazard ratios (HR) and 95% confidence intervals (CI) ranged from HR = 1.35 (95% CI: 1.25, 1.46) to HR = 1.36 (95% CI: 1.27, 1.44). Black/White differences in the cumulative incidence of treatment initiation at 3, 6, and 12 months were also significant and persistent across time periods, ranging from 0.09 (95% CI: 0.02, 0.15) to 0.11 (95% CI: 0.05, 0.17). Contrary to our hypothesis, Black/White disparities were not increasing over time.

Our results suggest that Black patients initiate MM treatment later than White patients and are less likely to ever initiate treatment. Contrary to our hypothesis, Black/White disparities are not increasing over time and have remained static.